MODELING CELLULAR SYSTEMS AND AGING PROCESSES: II. SOME THOUGHTS ON DESCRIBING AN ASYNCHRONOUSLY DIVIDING CELLULAR SYSTEM

1982 ◽  
pp. 1023-1035 ◽  
Author(s):  
Matthew Witten
Keyword(s):  
Cellular System ◽  
Cellular Systems

PERFORMANCE ANALYSIS OF RESOURCE ALLOCATION TECHNIQUES FOR POWER CONTROL IN DEVICE-TO-DEVICE CELLULAR SYSTEMS

2020 ◽  
Vol 5 (2) ◽  
pp. 45-59
Author(s):  
I.A. Olaoluwa ◽  
M.A. Adedoyin ◽  
A.I.O. Yussuff
Keyword(s):  
Resource Allocation ◽  
Service Delivery ◽  
Power Control ◽  
Base Station ◽  
Cellular System ◽  
Cellular Systems ◽  
System Capacity ◽  
Control Technique ◽  
Device To Device ◽  
Allocation Strategies

Recent development in pairs of devices communications in the cellular system has necessitated the emergence of various resource allocation strategies for power control with the hope of achieving higher data rate, enhanced system capacity and overall spectral efficiency. Strategies for efficient service delivery in device-to-device (D2D) cellular system have often posed daunting challenges requiring uncompromising techniques. In this work, various techniques for resource allocation strategies for power control in D2D cellular system are investigated. This work is dedicated at the best technique of achieving maximum transmission power of users of cellular and the device pair users with reference to the efficient service delivery coupled with established signal-to-interference-plus-noise ratio (SINR) at the base station and the D2D users across the channel of the uplink because of the ability of the individual transmitter of devices have been able to realign with the power of transmitter relative to the calculated SINR and interference parameters. An expression of SINR, D2D pairs and the distance between device pairs with respect to base station for the optimized network for the various techniques are analyzed. The performance of the resource-based power control technique (RPCT) and the adaptive power control technique (APCT), with respect to the SINR and the device pairs, has shown effectiveness in its ability to address over forty-three pairs of D2D in order to have an improved level of SINR as obtained in this work, it is convenient to say that an increase in the number of cellular users, enables a corresponding increase in the total capacity of D2D users. When an increase is experienced in the number of users of cellular, it automatically adds a value of increase to the reusable channels thereby enabling additional quantity of D2D users in the clusters, such that co-channel interference within the D2D users in the neighboring cluster reduces, thereby enabling an increased capacity of the user of D2D.

Cognitive Cellular Systems: A New Challenge on the RF Analog Frontend

Frequenz ◽  
2016 ◽  
Vol 70 (7-8) ◽  
Author(s):  
Gabor Varga ◽  
Moritz Schrey ◽  
Iyappan Subbiah ◽  
Arun Ashok ◽  
Stefan Heinen
Keyword(s):  
Data Transfer ◽  
Frequency Converter ◽  
Cognitive Radios ◽  
Intermediate Frequency ◽  
Local Oscillator ◽  
Cellular System ◽  
Cellular Systems ◽  
Technical Factor ◽  
Radio System ◽  
Cognitive Engine

AbstractCognitive Cellular Systems are seen today as one of the most promising ways of moving forward solving or at least easing the still worsening situation of congested spectrum caused by the growing number of users and the expectation of higher data transfer rates. As the intelligence of a Cognitive Radio system is located in the digital domain – the Cognitive Engine and associated layers – extensive research has been ongoing in that domain since Mitola published his idea in 1999. Since, a big progress has been made in the domain of architectures and algorithms making systems more efficient and highly flexible. The pace of this progress, however, is going to be impeded by hard requirements on the received and transmitted signal quality, introducing ultimate challenges on the performance of the RF analog frontend, such as in-band local oscillator harmonics, ultra low sensitivity and ultra high linearity. The RF frontend is thus likely to become the limiting technical factor in the true realization of a Cognitive Cellular System. Based on short recapitulations of the most crucial issues in RF analog design for Cognitive Systems, this article will point out why those mechanisms become responsible for the limitation of the overall performance particularly in a broadband Cognitive Cellular System. Furthermore, as part of a possible solution to ease the situation, system design of a high intermediate frequency (IF) to UHF frequency converter for cognitive radios is discussed and the performance of such a converter analyzed as a proof of concept. In addition to successfully tackling some of the challenges, such a high-IF converter enables white space operation for existing commercial devices by acting as frequency converter. From detailed measurements, the capabilities in both physical layer and application layer performance of a high-IF frontend developed out of off-the-shelf components is explained and is shown to provide negligible degradation to the commercial device being connected to.

A Comparative study on Handoff Algorithms for GSM and CDMA Cellular Networks

2017 ◽  
Vol 7 (3) ◽  
pp. 1219
Author(s):  
S. Neeraja ◽  
G. Sasibhushana Rao
Keyword(s):  
Cellular Networks ◽  
Mobile Communications ◽  
Cellular System ◽  
Cellular Systems ◽  
Efficient Utilization ◽  
Propagation Models ◽  
Soft Handoff ◽  
Continuous Service ◽  
Digital Cellular

The GSM, CDMA cellular systems are most trendy 2G and 3G digital cellular telecommunications systems, which is widely used throughout the world. These systems have many advantages such as high security, higher quality of call transmission over the long distances, low transmitted power, and enhanced capacity with more efficient utilization of the frequency spectrum. With these advantages these cellular systems have attracted more subscribers with more attention in the field of mobile communications. One of the most attractive features of cellular system is handoff which is a continuation of an active call when the mobile is moving from one cell to another without disconnecting the call. Usually, continuous service is achieved by efficiently designed handoff algorithms. So, efficient handoff algorithms are necessary for enhancing the capacity and QoS of cellular system. In this paper, the handoff analysis for GSM, CDMA cellular networks are done under various propagation models. Various handoff algorithms of GSM are described and also a novel received signal strength (R<sub>SS</sub>) based GSM handoff algorithm with adaptive hysteresis is analyzed. CDMA Soft handoff algorithm is analyzed and effective soft handoff parameters are estimated for better performance. The Comparison of handoff algorithms is studied based on results.

Label-free, mass-sensitive single-molecule imaging using interferometric scattering microscopy

2020 ◽  
Author(s):  
Nikolas Hundt
Keyword(s):  
Single Molecule ◽  
Cellular Systems ◽  
Single Molecule Imaging ◽  
Label Free ◽  
Measurement Sensitivity ◽  
Mass Distributions ◽  
Quantitative Measurements ◽  
Contrast Mechanism ◽  
Cellular Components ◽  
Scattering Signal

Abstract Single-molecule imaging has mostly been restricted to the use of fluorescence labelling as a contrast mechanism due to its superior ability to visualise molecules of interest on top of an overwhelming background of other molecules. Recently, interferometric scattering (iSCAT) microscopy has demonstrated the detection and imaging of single biomolecules based on light scattering without the need for fluorescent labels. Significant improvements in measurement sensitivity combined with a dependence of scattering signal on object size have led to the development of mass photometry, a technique that measures the mass of individual molecules and thereby determines mass distributions of biomolecule samples in solution. The experimental simplicity of mass photometry makes it a powerful tool to analyse biomolecular equilibria quantitatively with low sample consumption within minutes. When used for label-free imaging of reconstituted or cellular systems, the strict size-dependence of the iSCAT signal enables quantitative measurements of processes at size scales reaching from single-molecule observations during complex assembly up to mesoscopic dynamics of cellular components and extracellular protrusions. In this review, I would like to introduce the principles of this emerging imaging technology and discuss examples that show how mass-sensitive iSCAT can be used as a strong complement to other routine techniques in biochemistry.

Achievable Capacity of Closed/Open-Access Cognitive Radio Systems Coexisting with a Macro Cellular Systems

2012 ◽  
Vol E95-B (4) ◽  
pp. 1190-1197
Author(s):  
Hiromasa FUJII ◽  
Hiroki HARADA ◽  
Shunji MIURA ◽  
Hidetoshi KAYAMA
Keyword(s):  
Cognitive Radio ◽  
Open Access ◽  
Cellular Systems ◽  
Cognitive Radio Systems ◽  
Radio Systems ◽  
Macro Cellular

Design a Cellular System with Different Cluster Size and Investigate the Co Channel Interference Assuming a Limited Geographical Area with Fixed Channel Assignment Strategy

2017 ◽  
Vol 3 (04) ◽  
Author(s):  
Md.Taz Uddin, Ahmed al Marzean, Md Rafiqul Islam, Shahjahan Ahmed
Keyword(s):  
Channel Assignment ◽  
Cluster Size ◽  
Geographical Area ◽  
Cellular System ◽  
Communication Industry ◽  
Mobile Operator ◽  
Channel Interference ◽  
Assignment Strategy ◽  
Fixed Channel Assignment ◽  
Mobile Communication Industry

There are different communication standards in present mobile communication industry. Each of this standards has its own feature, architecture, and channel assignment strategies. Each mobile operator uses one of any standard and their aim is to support as much user as possible to communicate with tolerable interference. For that reason they use different cluster size and frequency planning to cover entire geographical area. To reuse the given bandwidth within the entire geographical area some cells uses same sets of frequency and interference arise when the distance between these cells is small. Also when distance is large then capacity is going low. In this thesis our work is to investigation the co channel interference among different cluster size assuming a limited sub urban geographical area in a cellular GSM network. Also we calculate the number of users using each of this cluster size and finally design a cellular system in this geographical area using best results (minimum interference and maximum capacity).

A Photoactivable Formaldehyde Donor with Fluorescence Monitoring Reveals Threshold to Arrest Cell Migration

2019 ◽  
Author(s):  
Lukas P Smaga ◽  
Nicholas W Pino ◽  
Gabriela E Ibarra ◽  
Vishnu Krishnamurthy ◽  
Jefferson Chan
Keyword(s):  
Wound Healing ◽  
Cell Migration ◽  
Fluorescence Enhancement ◽  
Biological Effects ◽  
Cellular Systems ◽  
Live Cells ◽  
First Report ◽  
Cell Lysate ◽  
Intracellular Release ◽  
Biological Analytes

Controlled light-mediated delivery of biological analytes enables the investigation of highly reactivity molecules within cellular systems. As many biological effects are concentration dependent, it is critical to determine the location, time, and quantity of analyte donation. In this work, we have developed the first photoactivatable donor for formaldehyde (FA). Our optimized photoactivatable donor, photoFAD-3, is equipped with a fluorescence readout that enables monitoring of FA release with a concomitant 139-fold fluorescence enhancement. Tuning of photostability and cellular retention enabled quantification of intracellular FA release through cell lysate calibration. Application of photoFAD-3 uncovered the concentration range necessary for arresting wound healing in live cells. This marks the first report where a photoactivatable donor for any analyte has been used to quantify intracellular release.

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